Machine for casting and trimming battery plate grids

ABSTRACT

A machine for trimming and stacking lead-acid battery electrode grids has a single pair of blades for cutting off first the feet and bottom edge, and then the top edge of each casting. The grids are delivered from the casting mould on to a sloping slide on which each grid slides down past the blades to an upper stop for the first cut and then to a lower stop for the second cut. The lower stop has a transfer plate on which the grid is swung up to a vertical position to join a stack suspended on a pair of rails.

United States Patent MACHINE FOR CASTING AND TRIMMING BATTERY PLATE GRIDS 12 Claims, 8 Drawing Figs.

US. Cl 164/262, 83/395, 83/419, 83/467, 83/903 Int. Cl ..B22d31/00,

[50] Field ofSearch 83/419, 903, 391, 394, 395,467,467 A; 164/262 Primary Examiner- Robert D. Baldwin AuorneyWatson, Cole, Grindle & Watson ABSTRACT: A machine for trimming and stacking lead-acid battery electrode grids has a single pair of blades for cutting off first the feet and bottom edge, and then the top edge of each casting. The grids are delivered from the casting mould on to a sloping slide on which each grid slides down past the blades to an upper stop for the first cut and then to a lower stop for the second cut. The lower stop has a transfer plate on which the grid is swung up to a vertical position to join a stack suspended on a pair of rails.

PATENTEUNUV 30 I97! SHEET 1 [1F 4 INVENTOR MAN J Gommuu Noam 1 AN Sunny PATENTEDuunuv 30 um 3, 623 540 SHEET 2 OF 4 nnnnnnn \25 nnnnnuun L nnn nnn nu unn nun F] nun nun u nun nnn nun nun nun nnn nnn nun nnu nnn n nun unn nu nu nu INVENTOR ALAN J G-ocuwum NMMAN Banana PATENTEDuuv 30 Ian 3. 623 540 sum 3 OF 4 INVENTOR ALAN J Qocbwlm Noam/u; Smmms MACHINE FOR CASTING AND TRIMMING BATTERY PLATE GRIDS This invention relates to machines for handling battery plate grids and is mainly concerned with the arrangement of the machine for trimming the grids when cast.

According to the present invention a machine for trimming lead acid battery electrode grids includes a slide sloping down past cooperating blades, and one or more stops spaced and acsure plate on its upstream side to grip part of the grid while it is being trimmed.

face with a previous grid.

Conveniently each grid has a pair of laterally projecting lugs near its upper edge and the lower stop swings it into a vertical plane with its lugs resting on a pair of rails, between which it hangs down.

In one form of the invention the machine is combined with a mol casting falling out and which terminates so that the casting reaches an oblique slide down which it slides to the cutter.

Further features and details of the invention will be apparent from the following description of one specific embodiment which will be given by way of example with reference to the accompanying somewhat diagrammatic drawings which:

FIG. 1 is a general perspective view of a machine for casting, trimming and stacking battery plate grids;

FIG. 2 is a view of a typical grid as cast;

FIG. 3 is a diagrammatic side view of the machine showing the relationship of the various parts at one stage of the cycle;

FIG. 4 is a view similar to FIG. 3 with the parts at another stage of the cycle;

FIG. 5 is a somewhat seen from downstream;

FIG. 6 is a similar demeath; and

FIG. 7 is a section of the line 7-7 of FIG. 5; and

FIG. 8 is a view of a modified construction for transferring the casting from the mold.

As shown in FIG. 1 the machine comprises a mold 10 consisting of a pair of slabs l1 and 12, orientated in a vertical plane in order that the molten lead may flow satisfactorily and fill all the narrow passages required to form the grid.

Molten lead from a lead pot (omitted from the drawing for more detailed view of the guillotine view of the guillotine seen from uneach casting.

As shown in FIG. 2 each casting 20 comprises the grids for two plates with a pair of feet 21 projecting from the bottom of The machine comprises an oblique slide or platform 30 sloping down from a point below the mold, past a guillotine 40 to a lower stop and transfer plate 70. The upper end of the slide 30 is formed by a flat water-cooled cooling bed 31.

The mold is provided with a ejecting means for releasing the cut along the line 25 to trim off the sprue. The grid is finally transferred to a pair of rails where a stack of castings accumulate hanging down between the rails with their lugs resting on the rails.

In the arrangement shown in the drawings the casting falls from the mold and lands on the flat oblique cooling bed 31 so that no separate flattening operation is needed.

In an alternative arrangement, not illustrated, the casting is which is then tilted to the required has been found unnecessary to incorporate a separate straightening operation.

timony, say ID to 12 but this has certain undesirable results on THE MOLD The mold is generally of conventional construction comprising a fixed slab 11 at the back or upstream side, and a moving slab 12 at the front or downstream side. The moving slab 12 is supported on guide rods so as to remain parallel to the fixed slab as it is moved towards and away from it by the action of a pneumatic cylinder. The fixed slab has in it a number of openings through which ejector pins extend so that when the moving slab has moved away from the fixed slab a short distance the pins will be projected to eject the casting from the fixed slab,

The means for ejecting the cast grid from the mold are arranged so that the cast grid turns as it falls towards an oblique position so as to land substantially flat on the water-cooled cooling bed 3l. The cast grid is prevented from sliding down by the engagement of its lower edge with a cooling stop in the form of a curved spring steel plate 32 carried at the upper ends by a pair of vertical arms 33 which are pivoted at their lower ends 34. The cast grid remains on the cooling bed for perhaps half a minute to allow it to cool, after which the cooling stop is moved about the pivot 34 to allow the grid to pass under it and slide down to the guillotine 40.

THE GUILLOTINE AND TRANSFER STACKING UNITS The guillotine unit comprises a fixed blade 41 forming the lower front end of the sloping platform or slide 30, and a moving blade 42 carried by a beam 43 mounted to slide on guide rods 44 projecting perpendicularly to the plane of the sloping platform and having connecting rods 45 at its ends connected to cranks (not shown) at opposite ends of a rotating shaft to move it towards and away from the fixed blade. The moving blade has an oblique cutting edge and is set to rub against and cross the edge of the fixed blade with a scissor action to shear the metal of the grid.

An upper stop bar 50 is positioned on the downstream side of, and moves in sympathy with, the moving blade. Thus the beam 43 carrying the moving blade also carries a pair of guide rods 51 which pass through bushes in the ends of the upper stop bar 50. As best seen in FIG. 6 the upper stop bar is provided with a buffer bar 52 urged upstream away from it by a number of leaf springs 53 such movement being limited by stops constituted by bolts 54 passing through the stop bar. Thus the engagement of a cast grid with the bufier bar 52 is cushioned, but the bulTer bar returns to a predetermined posi tion so that the grid is precisely located in a suitable position for cutting.

The downward movement of the upper stop bar 50 is limited in four different ways. First the guide rods 51 are provided with circlips 55 near their lower ends to limit the extend the bar can slide down them (see FIG. Secondly a pair of adjustable stop screws 56 projecting up from a fixed beam 57 set a bottom limit to the extent that the upper stop bar can descend in relation to the fixed blade 41. When the bar engages these stop screws the bufler bar will be in an operative position, so as to stop a cast grid from sliding further down the slide.

Thirdly the moving blade is provided with a pair of ball catches 58 projecting from its downstream surface so as to engage recesses 59 in the upstream face of the upper stop bar when the latter is in its uppermost position in relation to the moving blade.

Fourthly the support for the lower stop, described below, has a pair of projecting horns 79 which, when the lower stop is in its upstream position, engage under the ends off the upper stop bar to prevent it from falling to its operative position, and hold it up in a position such that a cast grid can pass under it.

The beam 43 carrying the moving blade is also provided with a pressure plate 60 carried by guide rods 61 passing through guides in the beam and urged downwards relatively to the latter by springs 62 so as to grip the cast grid, or the sprue, while the guillotine makes a cut.

The upward movement of the upper stop bar 50 is limited by fixed stops 65, which thereby serve to disengage the ball catches as described more fully below.

4 THE LOWER STOP AND TRANSFER PLATE Cooperating with the guillotine unit is a lower stop and transfer plate comprising a plate 71 with a flat face that can be brought to an upstream position in which it forms virtually a downward continuation of the sloping platform (roughly as shown in FIG. 4) and a lower stop bar 72 extending horizontally across it to form a stop for the lower edge of a grid during its second cut.

The lower stop and transfer plate is carried by a pair of downwardly projecting arms 73 pivoted at their lower ends at 74 on a pair of bellcranks 75 mounted on a horizontal transverse shaft 76 and provided with a stop rod 77 which engages the arms after a certain angular movement in a clockwise direction (as viewed in FIGS. 3 and 4). The shaft 76 is oscillated by a further crank and connecting rod driven by an eccentric, not shown.

In the position shown in FIG. 4 the arms 73 rest on a fixed transverse rod 78 and the plate 7] lies slightly below the plane of the slide and terminates close to the cutting edge of the fixed blade. As the bellcranks 75 turn in a clockwise direction, the lower stop bar and transfer plate are withdrawn in a downstream direction and at the same time slightly tilted in an anticlockwise direction about the fixed rod 78. When the lower stop and transfer plate have been withdrawn a certain distance in a downstream direction the stop rod 77 of the bellcrank engages the arms 73 so that the latter, with the lower stop bar and transfer plate, turn with the bellcranks in a clockwise direction towards a vertical position as indicated in FIG. 3. As they do so, with the cast grid 20 resting on the plate and its lower edge against the stop bar in the manner of a bookrest, the grid is delivered to a pair of rails 80 on which the finished grids are stacked.

To enable the grid to be transferred to the rails the latter are provided at the forward ends with downwardly and outwardly curved portions forming horns 81 located so that the paths of the lugs and the vertical sides of the grid will intersect them at a small angle as the transfer plate swings up, so that the lugs are gently centralized and transferred to the horns and pushed along them. Thus the grid is added to the stack of grids already on the rails and pushes them along a distance corresponding to its own thickness.

The lower stop bar 72 is of obtuse angled V-section and is pivoted to the arms 73 abut an axis 82. This axis is so located in relation to the center of gravity of the lower stop bar that as the arms 73 approach a vertical position, the stop bar topples over in a clockwise direction about its pivot 82 to the position shown in FIG. 3. This has no effect on the grid, which by this time is supported on the guide rails, but it tilts the V-section stop bar so as to tip off any chips or cuttings which might otherwise interfere with the accurate positioning of the next grid. When the arms 73 return in an anticlockwise direction the stop bar swings back to its initial position under gravity.

As already mentioned the arms 73 are provided with a pair of extensions or horns 79 which in the upstream position of the FIG. 4 hold up of the upper stop bar while a grid is sliding under it on the transfer plate.

DRIVE UNIT The machine is electrically driven through reduction gearing and a stepless speed change unit so that the casting rate can be adjusted to suit the type of grid being produced.

The cooling stop is driven at the same frequency as the lower stop and transfer plate but the guillotine is driven at twice this frequency. Thus during a complete cycle of movement the cooling stop 32, and the lower stop and transfer plate 70, the guillotine descends twice. During the first cut the lower stop is swung away to the region of the position shown in FIG. 3 so that its horns 79 cannot prevent the upper stop bar 50 from falling to its operative position. During the second cut the lower stop is in the region of the position shown in FIG. 4 in which its horns 79 hold the upper stop bar clear of the grid.

OPERATION It is believed that the operation will generally be clear from the description of the construction given above.

As already indicated, when a grid has been cast the mold is falls, turning as it does so,

sliding down by the After an appropriate period for cooling, ample be half a minute, the cooling stop is which may for exlugs supported on top ofthem.

When the stop bar and grid.

In a modified construction shown in FIG. 8 the guillotine is as described above but the arrangement for transferring the casting from the mold to the sloping slide differs.

in this construction, when the casting is ejected from the down the sloping platform to the guillotine unit.

We claim: 1. A machine for trimming lead-acid battery electrode grids,

tive and inoperative positions in synchronism with the blades but at half the frequency, said stops being so located that the claim 3 wherein said preventing means comprises a part connected to the lower stop arranged inoperative position, during alternate cutting strokes of the blade.

5. A machine as claimed in grid.

7. A machine as claimed in claim 6 including a pair of rails so situated that, if each grid has a pair of laterally projecting which it hangs down.

8. A machine as claimed in claim plane of the sloping slide, and a flat-cooling and is placed so 9. A machine as claimed in claim 8 in which the cooling plate is provided with a cooling stop to stop a grid in a position resting on it.

10. A machine as claimed in claim I in combination with a mold for casting each grid in a substantially vertical plane and a carrier adapted to receive a casting from the mold in a substantially vertical plane and to tilt with it into a plane substantially in line with the upper end of the slide.

1 l. A machine as claimed in claim 10 in which the carrier is in the form of a chute into which the casting falls vertically in its own plane and which is pivoted about an axis in or parallel to the said plane above the chute to tilt to an oblique plane.

12. A machine as claimed in claim 11 in which the chute is open at the bottom but provided with a stationary curved stop which prevents the casting falling out and which terminates so that the casting clears it as it reaches a position in line with the upper end of the slide 

1. A machine for trimming lead-acid battery electrode grids, including a slide sloping down past cooperating blades and for engaging a grid sliding down the slide to locate it for trimming by the blades, an upper cutting stop and a lower cutting stop and means for moving at least the upper stop between operative and inoperative positions in synchronism with the blades but at half the frequency, said stops being so located that the upper stop locates a grid in a position for its lower edge to be trimmed off by a first cut of the blades, whereafter the grid slides down until the lower stop locates it at a position for its upper edge to be trimmed off by a second cut of the same blades.
 2. A machine as claimed in claim 1 in which the blades are respectively fixed and moving and the upper stop is connected to the moving blade by a releasable connection so as to be lifted to an Inoperative position as the moving blade moves up away from the fixed blade whereupon the connection is released to allow the upper stop to return to an operative position before the moving blade descends for the first cut, and means for preventing the upper stop from returning to its operative position prior to alternate cuts.
 3. A machine as claimed in claim 2 in which the connection comprises a catch, such as a ball catch, released by relative movement, and the movement of the upper stop is limited by limiting stops located so that the catch will be engaged when the blade is in the region of its lowermost position and released when the upper stop reaches its highest position but the blade continues to rise.
 4. A machine as claimed in claim 3 wherein said preventing means comprises a part connected to the lower stop arranged to support the upper stop in an inoperative position, during alternate cutting strokes of the blade.
 5. A machine as claimed in claim 3 in which the moving blade also carries a resiliently mounted pressure plate on its upstream side to grip part of the grid while it is being trimmed.
 6. A machine as claimed in claim 5 in which the lower stop is mounted to swing about a transverse axis to carry each grid in turn to a stack in which it lies face to face with a previous grid.
 7. A machine as claimed in claim 6 including a pair of rails so situated that, if each grid has a pair of laterally projecting lugs near its upper edge, the lower stop will swing it into a vertical plane with its lugs resting on said pair of rails, between which it hangs down.
 8. A machine as claimed in claim 7 in combination with a mold for casting each grid in a substantially vertical plane, having ejecting means for ejecting the cast grid so as to turn as it falls towards the plane of the sloping slide, and a flat-cooling plate which forms the upper end of the slide and is placed so that the grid will fall on to it.
 9. A machine as claimed in claim 8 in which the cooling plate is provided with a cooling stop to stop a grid in a position resting on it.
 10. A machine as claimed in claim 1 in combination with a mold for casting each grid in a substantially vertical plane and a carrier adapted to receive a casting from the mold in a substantially vertical plane and to tilt with it into a plane substantially in line with the upper end of the slide.
 11. A machine as claimed in claim 10 in which the carrier is in the form of a chute into which the casting falls vertically in its own plane and which is pivoted about an axis in or parallel to the said plane above the chute to tilt to an oblique plane.
 12. A machine as claimed in claim 11 in which the chute is open at the bottom but provided with a stationary curved stop which prevents the casting falling out and which terminates so that the casting clears it as it reaches a position in line with the upper end of the slide. 